1. Technical Field
The present invention relates to a technique for emphasizing bass sounds of an audio signal.
2. Background Art
In order to emphasize the low-frequency components of a sound emitted from a speaker, usually, the level of the low-frequency components is increased. Sometimes, a small-diameter speaker or the like cannot emit the low-frequency components depending on its characteristics. In such a case, a technique is employed in which harmonics of the low-frequency components are generated and added to the original sound, thereby causing the sound to be listened as if the low-frequency component is expanded, while using the phenomenon which is called Missing fundamental (see, for example, JP-T-11-509712).
According to the technique, a person can listen the sound as if the low-frequency component is expanded. However, the low-frequency component is different from the original one. Therefore, there is a case where a sense of strangeness such as a change in sound quality and distortion is caused depending on the processing method.